arXiv subjects

Manabputra

Publications and source records attributed to Manabputra.

3 recordsLinked to original sources

arXiv2024

Lattice Hamiltonians and Stray Interactions Within Quantum Processors

Developing Hamiltonian models for quantum processors with many qubits on the same chip is crucial for advancing quantum computing technologies. Stray couplings between qubits lead to errors in gate operations. This study underscores the importance of incorporating lattice Hamiltonians into quantum circuit design. By comparing many-body effects with two-body stray couplings, we show how adjusting circuit parameters can enhance two-qubit gate fidelity. We find that loosely decoupled qubits result in weaker stray interactions and higher gate fidelity, challenging conventional assumptions. We investigate the scenario where three-body $ZZZ$ interaction surpasses two-body $ZZ$ interactions, highlighting the transformative potential of lattice Hamiltonians for novel multi-qubit gates. Moreover, we investigate the cross-resonance gate within the lattice Hamiltonian framework and examine the impact of microwave pulses on stray coupling. This emphasizes the necessity of developing a comprehensive theoretical framework that includes lattice interactions, which are now critical given the sophistication of contemporary quantum hardware. These insights are vital for developing fault-tolerant quantum computing and next-generation quantum processors.

quant-ph↗

arXiv2020

A simulational model for witnessing quantum effects of gravity using IBM quantum computer

Witnessing quantum effects in the gravitational field is found to be exceptionally difficult in practice due to lack of empirical evidence. Hence, a debate is going on among physicists whether gravity has a quantum domain or not. There had been no successful experiments at all to show the quantum nature of gravity till two recent independent works by Bose et al. [Phys. Rev. Lett. 119, 240401 (2017)] and by Marletto and Vedral [Phy. Rev. Lett. 119, 240402 (2017)]. The authors have proposed schemes to test the quantumness of gravity in two small test masses by entangling two spatially separated objects using gravitational interactions. They provide a method to witness the entanglement using spin correlation measurements, which could imply evidence for gravity being a quantum coherent mediator. Here we propose a simulational model by providing a new quantum circuit for verifying the above schemes. We simulate the schemes for the first time in IBM's 5-qubit quantum chip 'ibmqx4' by developing a quantum system which shows effects analogous to quantum gravity and calculates the degree of entanglement of the spin correlation. The entanglement witness over a range is obtained for different experimental parameters.

quant-ph↗

arXiv2018

Generalization and Demonstration of an Entanglement Based Deutsch-Jozsa Like Algorithm Using a 5-Qubit Quantum Computer

This paper demonstrates the use of entanglement resources in quantum speedup by presenting an algorithm which is the generalization of an algorithm proposed by Goswami and Panigrahi [arXiv:1706.09489 (2017)]. We generalize the algorithm and show that it provides deterministic solutions having an advantage over classical algorithm. The algorithm answers the question of whether a given function is constant or balanced and whether two functions are equal or unequal. Finally, we experimentally verify the algorithm by using IBM's five-qubit quantum computer with a high fidelity.

quant-ph↗